1. Field of the Invention
The present invention relates to a card connector. More particularly, the present invention relates to a connector suitable for connecting a subscriber identity module (SIM).
2. Description of the Related Art
If a manufacturer/distributor of a cellular phone (portable telephone) terminal is different from a telecommunications carrier, a card-type subscriber identity module (hereinafter, referred to as a SIM card) is used for authenticating a subscriber of the telecommunications carrier.
For example, as described in Japanese Patent Application Laid-Open Publication No. 2004-228694, a connector is provided on a back side of a main body of a portable telephone terminal. The connector has a contact element to be contacted with an electrode of the SIM card and when the SIM card is inserted into the connector, the contact element is contacted with the electrode of the SIM card to enable to read a subscriber identity code stored in the SIM card.
Generally, a back-side cover used also as a battery is configured to be closed while the SIM card is inserted into the connector. When used in such a state, due to a requirement for miniaturizing and thinning a portable telephone terminal device, the card connector is also required to be thinned inevitably. A dimensional tolerance of the card inserted into the card connector is on the order of ±0.1 mm. Therefore, while being inserted into the connector, the SIM card may be rattled in the connector.
Such rattles generates intermittent discontinuity of power supply due to poor contact, which generates voltage drop, and has a considerable effect on a speech quality as a system.
As a specific configuration example of the SIM card connector, an invention described in Japanese Patent Application Laid-Open Publication No. 2000-260537 is known. FIG. 1 is a perspective view of a SIM card connector described in Japanese Patent Application Laid-Open Publication No. 2000-260537. The SIM card connector is constituted by a cover 17 holding the SIM card on both sides and a contact support unit 14 comprising contact elements 35 with a spring property disposed on a panel portion 18.
The cover 17 has arms 55 at one end, and a hinge portion 56 at the tips of the arms 55 engage with openings 26 of support blocks 24 of the contact support unit 14. The cover 17 has locking tabs 48 at the other end.
The contact support unit 14 has the support blocks 24 and slots 30 on the other side.
When the SIM card 1 is held and the cover 17 is closed, the cover 17 is rotated around a turning axis 60 of the hinge portion 56 against the spring property of the contact elements 35 and is brought down to the contact support unit 14. The cover 17 is slid to the slots 30 to insert the locking tabs 48 at the end of the cover into the slots 30 of the contact support unit 14.
With such a configuration, the SIM card can be held with the contacts of the SIM card in contact with the contact elements 35.
In the invention described in Japanese Patent Application Laid-Open Publication No. 2000-260537, engagement and retention between the cover 17 and the contact support unit 14 is achieved by applying resistance against movement of the cover with a spring property of the contact elements 35 while the locking tabs 48 at the end of the cover are inserted into the slots 30 of the contact support unit 14 and by applying a cam 260 provided in the opening 26 to the hinge means 56 to apply resistance against movement in the horizontal direction (back-and-forth direction).
Therefore, the invention described in Japanese Patent Application Laid-Open Publication No. 2000-260537 is configured to open, close and hold the cover solely with movement of the cover 17 in the back-and-forth direction. Therefore, impact or vibration in the back-and-forth direction may slide and move the cover to release the engagement between the cover and the contact support unit 14. In such a case, the credibility of the electric connection is damaged between the electrodes of the SIM card and the contact elements 35, and a system is affected by signal discontinuity, voltage drop, etc.
In the invention described in Japanese Patent Application Laid-Open Publication No. 2000-260537, the turning of the cover 17 is configured to be performed around the hinge means 56 provided at the ends of arms 55 extending from the cover 17. The vertical width of the openings 26 of the support blocks 24 must have a size allowing the hinge means 56 to slide.
Therefore, in consideration of lowering the height of the card connector as a whole, if the height of the support blocks 24 is lowered, the wall thickness around the openings 26 must be thinned because of the vertical width of the openings 26. In such a case, in combination with the use of the arms 55, the strength is inevitably reduced. Therefore, the lowering of the height of the card connector is constrained.